Chain of Evidence by Pearson, Ridley

like new, signed by author on title page without inscription, first edition with full number line. Police lieutenant Joe "Dart" Dartelli made one critical mistake in his police career. Three years ago, he chose to ignore a piece of evidence in a suicide case--a suicide that may possibly have been a murder--because the dead man was himself a vicious woman-killer who more than deserved his fate. And, the evidence that Dart ignored could have raised difficult questions about his former mentor, the brilliant forensic scientist Walter Zeller. But now another suicide victim has turned up--the body of a wife beater--and Zeller has disappeared from the face of the earth. With nothing to tie the cases together except some strange blood chemistry, the case is officially closed. But Dart knows in his deepest heart that Zeller is on some twisted vigilante crusade, and that it will happen again. Unless Dart stops it.